WASHINGTON, June 20 (Reuters) - An instructor who provoked debate in his classroom of military officers by suggesting the United States was at war with Islam has been relieved of teaching duties at a military college and the course ordered redesigned, the Pentagon said on Wednesday.

The course at the Joint Forces Staff College in Norfolk, Virginia, part of the U.S. National Defense University, had been offered since 2004, according to Colonel David Lapan, spokesman for the chairman of the U.S. military's Joint Chiefs of Staff.

Lapan said "institutional failures in oversight and judgment" resulted in changes to the content about two years ago that resulted in inappropriate materials being introduced.

These materials included one slide that asserted "the United States is at war with Islam and we ought to just recognize that we are (at) war with Islam," Pentagon officials said in April when they launched a review of the course in response to a student complaint.

The instructor was a U.S. military officer. Lapan declined to identify the instructor by name, citing privacy requirements.

Discovery of the course material embarrassed the military at a time when U.S. officials are trying to mend ties with the Muslim world following a spate of incidents in Afghanistan, including the burning of copies of the Koran and pictures showing U.S. soldiers posing with corpses of Afghans.

Lapan said an inquiry found the initial course content in 2004 was fine but "over time bad decisions and poor judgment was exercised in how the course was modified."

"The inquiry recommends the course be redesigned to include aspects of U.S. policy and reduce its reliance on external instruction," Lapan said in a statement.

"The elective course's military instructor has been relieved of his instructor duties until his permanent change of station, which was previously planned for 2012," the statement said.

It was not immediately clear how many students at the college for top military officers had taken the course over the past two years, but Lapan said there were no plans to offer new training to update them on U.S. policy toward Islam.

Lapan said the instructor used provocative statements about Islam in an effort to stimulate thinking and debate in the classroom.

"It was meant to be something ... to stimulate discussion and challenge people's beliefs," Lapan said. "The flaw was that it didn't clearly define that it was meant to be provocative."

The inquiry also recommended a review of actions by two civilian employees at the staff college to see if disciplinary action was merited because of their failure to exercise proper oversight, Lapan said. Administrative counseling was recommended for a second military officer, he said.

Lapan said the course content was considered inappropriate because it failed to include U.S. government policy on countering extremism and "the material on Islam ... was presented almost all in a negative light."

"It was not focusing on certain radical elements of Islam that do provide a threat but instead painting all of Islam in a negative light," he said.

Army General Martin Dempsey, chairman of the Joint Chiefs of Staff, ordered the review of the course on Islam and military education in general after a soldier complained about the content of the course entitled "Perspectives on Islam and Islamite Radicalism" at the college in Norfolk, officials said.